In the oil and gas industry tool connections are frequently used. For example, a downhole tool may be required to be secured to a deployment member, such as wireline or coiled tubing and be deployed into a wellbore to perform a desired function, such as sealing, data acquisition, flow control, production enhancement or the like. The downhole tool may be connected with one or more other tools to form a tool string. Such a tool string may include a tool which functions to operate the connected downhole tool. For example, the tool string may include a setting tool which is used to operate or actuate the downhole tool.
Also, in some instances a connection may need to be made with a tool already located within a wellbore, such as when a previously deployed tool is to be retrieved or where a tool may require to be fished from the well, for example following a failure, being accidentally dropped into the wellbore, and the like.
Many tool connections include a fail-safe release which can be activated to release the connection in certain circumstances. Such a fail safe may include sharable connections, for example, which may shear upon application of a predetermined force, such as axial force.
In the mechanical setting of a downhole tool, an overload safety may be provided in an associated setting tool, and in the event of activation of such an overload safety a recoil or jarring force may inadvertently activate a failsafe release in a connector holding the tool, causing disconnection of the tool and potentially dropping this through the wellbore.
Also, in some fishing operations it might be desirable to apply a jarring force to the downhole tool being retrieved, for example via a separate jarring tool coupled to or forming part of a fishing tool. In some cases the effect of a jarring tool may inadvertently release the connection between the fishing tool and downhole tool.